As we know, Doflamingo is actually a world noble. And I thought
of it, Brownbeard mentioned that a world noble gave the Punk Hazard
dragon a name. Also, Momonosuke saw a hallucination of Doflamingo
in his eastern dragon form. Since the dragon and the fruit was
artifically made by Vegapunk, perhaps Doflamingo found a way to
force him to work for him? That dragon was made to guard Punk
Hazard, so perhaps Doflamingo made Vegapunk create the dragon so no
one will find Caesar Clown. If you have any ideas, comment them.
This definitely makes perfect sense.

If the Straw Hats along with the samurai arrive at Wano Country,
I'll been thinking of ideas for the place.

The : A tribe of dwarves who use leaves as umbrellas.
Based on the Koropokkuru.

A young monk who has the power of the . He might idolize Usopp,
a reference to the Crow Tengu portrayed as an underling for
the long-nosed Great Tengu. See here, ﻿Tengu ~ 天狗 (てんぐ) ~ part of
The Obakemono Project: An Online Encylopedia of Yōkai and
Bakemono

The Snakeneck Tribe might, as their name states, have long
necks like a snake. Probably based on the Rokurokubi.

A group which may consist of people and races resembling yokai,
lead by an old man resembling Nurarihyon. Based on the Hundred
Demon Night Parade.